The effects of prophylactic bolus phenylephrine on hypotension during low-dose spinal anesthesia for cesarean section

BackgroundContinuously infused phenylephrine is frequently used to reduce the incidence of hypotension in women undergoing cesarean section under spinal anesthesia, but less is known about the prophylactic bolus method. We evaluated three prophylactic bolus doses of phenylephrine during low-dose spinal anesthesia for cesarean section.MethodsOne-hundred-and-eighty-four patients were randomized to receive 0.9% saline 2 mL (Control Group) or phenylephrine 1.0 μg/kg (PHE1 Group), 1.5 μg/kg (PHE1.5 Group), or 2.0 μg/kg (PHE2 Group) immediately after induction of combined spinal-epidural anesthesia. Maternal blood pressure and heart rate were recorded at 1-min intervals until delivery. Hypotension, defined as systolic blood pressure <80% of baseline, was treated with rescue doses of phenylephrine 100 μg at 1-min intervals until hypotension resolved. The incidence of nausea, vomiting, bradycardia, and hypertension, as well as Apgar scores and umbilical blood gases, were recorded.ResultsThe incidence of hypotension was 71.7% (33/46) in the Control Group, 68.9% (31/45) in the PHE1 Group, 37.0% (17/46) in the PHE1.5 Group and 45.7% (21/46) in the PHE2 Group (P=0.001). The total rescue dose of phenylephrine was greater in the Control Group than those in the PHE1.5 Group (P <0.05) and PHE2 Group (P <0.05). The incidence of hypertension increased as the dose of prophylactic phenylephrine increased (P <0.001) and was highest in the PHE2 group (37%). Other variables did not differ among the four groups.ConclusionsUnder the conditions of this study, prophylactic bolus injection of phenylephrine 1.5 μg/kg was a suitable alternative method for reducing the incidence of hypotension during low-dose spinal anesthesia for cesarean section.     

A prospective observational study of the change in regional cerebral oxygen saturation during cesarean delivery in women receiving phenylephrine prophylaxis for spinal hypotension

BackgroundSpinal hypotension causes decreased regional cerebral oxygen saturation (ScO₂) in women undergoing cesarean delivery. In this study we aimed to measure the change in ScO₂ using near infrared spectroscopy in women receiving a prophylactic phenylephrine infusion during cesarean delivery under spinal anesthesia.MethodsThis was a prospective, observational cohort study. Fifty-three women had ScO₂ measurements at the following time points: preoperatively, in the supine position with 30° of left lateral tilt; one and five minutes after spinal anesthesia; at the time of skin incision; immediately after delivery; one minute after commencing the oxytocin infusion; at completion of surgery, and one hour after surgery. Spinal anesthesia and a prophylactic phenylephrine infusion were administered according to a standard treatment protocol. Statistical analysis used the Wilcoxon Signed Rank test with Bonferroni’s correction for multiple comparisons.ResultsBlood pressure was maintained within 20% of baseline throughout surgery. The baseline mean (range) ScO₂ was 61.5% (54.0–66.3%). It decreased significantly at all subsequent measurement points. The maximum decrease was five minutes after spinal anesthesia. Thirty-four (64.2%) of the parturients exhibited ScO₂ values <20% of baseline, or a decrease to below an absolute value of 50%. There was no significant correlation between systolic blood pressure and mean ScO₂.ConclusionSpinal anesthesia with phenylephrine infusion during cesarean delivery is associated with a significant decrease in ScO₂ levels, maximal five minutes later. Further studies are required to establish the clinical significance of this finding.     

Noise levels during cesarean delivery: a prospective observational study

BackgroundExcessive noise has negative implications for both clinicians and patients. Emergency cesarean deliveries require rapid co-ordination and communication, possibly increasing noise pollution. We aimed to determine if noise levels in the Labor and Delivery operating room were higher during emergency cesarean deliveries than during non-emergency cesarean deliveries.MethodsWe conducted a prospective observational study measuring noise levels in Labor and Delivery operating rooms at a single academic medical center. Sound meters placed on anesthesia machines and events charted in the electronic medical record were used to correlate noise levels to clinical activity. Noise levels in all cesarean deliveries were recorded for one year. Deliveries were classified into two groups: non-emergency (routine or urgent) and emergency. We compared noise levels of the groups at eight time points of interest: anesthesia provider enters operating room (T1), induction (T2), five minutes before incision (T3), three minutes before incision (T4), one minute before incision (T5), time of incision (T6), delivery (T7), and five minutes before initiating emergence (T8).ResultsNoise levels were measured for 440 cesarean deliveries. Forty were classified emergency and 400 non-emergency (304 routine, 96 urgent) procedures. Emergency cesarean deliveries were noisier at all eight time points, although the absolute difference in decibels between the two groups was modest. The difference in noise level reached statistical significance at five time points (T1, T2, T5, T6, and T7).ConclusionNoise levels were higher during emergency than during non-emergency cesarean deliveries.     

Gastric emptying of carbohydrate drinks in term parturients before elective caesarean delivery: an observational study

BackgroundPre-operative carbohydrate (CHO) drinks have shown some benefits peri-operatively and have been incorporated into many Enhanced Recovery after Surgery (ERAS) programmes. We assessed the gastric emptying of pre-operative CHO drinks prior to elective caesarean delivery using ultrasonography.MethodsAfter a standard overnight fast, non-labouring pregnant women awaiting elective caesarean delivery underwent a standardised gastric ultrasound assessment at baseline and then every 20 min for 2 h after consuming 400 mL of a CHO drink. The gastric emptying was determined at each time-point both qualitatively and quantitatively. The primary outcome was the time taken for participants to return to a qualitative fasted Perlas grade of 0 or 1.ResultsThe gastric emptying of 40 participants was analysed. At baseline, all patients had a qualitative grade of either 0 or 1. All patients had returned to either grade 0 or 1 by 100 min. At 120 min the antral right lateral decubitus (RLD) cross-sectional area (CSA) was 8.03 cm² (95th percentile; 95% CI 7.4 to 8.3 cm²) and gastric volume per kg was 1.57 mL/kg (95th percentile; 95% CI 1.4 to 2.2). At 120 min there was no statistically significant difference from baseline for the RLD CSA (P=0.38) or gastric volume per kg (P=0.27).ConclusionsThe gastric emptying of this cohort of pregnant women suggests that 400 mL of a CHO drink can be safely consumed up to two hours before elective surgery. This study can help inform future peri-operative fasting guidelines for pregnant patients.     

A prospective observational study to investigate the relationship between local anesthetic infiltration pain before spinal anesthesia and acute and chronic postsurgical pain in women undergoing elective cesarean delivery

BackgroundCesarean delivery is one of the most common procedures performed worldwide. We conducted this prospective cohort study to evaluate the association between local anesthetic infiltration (LAI) pain prior to spinal anesthesia and pain and morphine consumption within 24 h after cesarean delivery (primary outcomes). A secondary objective was to assess the association between LAI pain and pain at one month postoperatively.MethodsRecruitment of 216 eligible women scheduled for elective cesarean delivery. Local infiltration before spinal anesthesia was performed using a 24-gauge needle and 3 mL 2% plain lidocaine. All subjects received 2.2 mL 0.5% hyperbaric bupivacaine with 200 µg morphine for spinal anesthesia. A 0–10 verbal numerical rating scale was used to assess LAI pain severity, and subsequent pain at 24 h, 1, 3 and 12 months.ResultsWe found a moderate correlation between LAI pain intensity and severity of acute pain at rest (rho=0.56, P <0.001) and with movement (rho=0.58, P <0.001) and a weak correlation with morphine consumption (rho=0.17, P=0.01) within 24 h postoperatively. We also found a positive correlation between LAI pain and the severity of persistent wound pain at rest (rho=0.30, P <0.001) and with movement (rho=0.52, P <0.001) at 1 month. The incidence of wound pain at 1, 3 and 12 months postoperatively was 37.1%, 7.0% and 1.4%, respectively.ConclusionsPain from LAI prior to spinal anesthesia is significantly associated with subsequent postoperative pain both acutely and at one month in women scheduled for elective cesarean delivery under spinal anesthesia.     

Pencil-point needle bevel direction influences ED50 of isobaric ropivacaine with fentanyl in spinal anesthesia for cesarean delivery: a prospective,double-blind sequential allocation study

BackgroundThere is little evidence on the influence of bevel direction of a pencil-point needle on the median effective dose (ED50) of isobaric ropivacaine and fentanyl in spinal anesthesia for cesarean delivery.MethodsIn this prospective, double-blind, sequential allocation study, 82 parturients scheduled for elective cesarean delivery under combined spinal-epidural anesthesia were included. We sought to determine the median effective dose of intrathecal 0.75% isobaric ropivacaine plus fentanyl 15 μg with two different bevel directions of a 26-gauge Whitacre needle using up-down sequential allocation. Parturients were randomly allocated to either Group Ce (needle aperture oriented in a cephalad direction) or Group Ca (aperture directed caudally). The initial dose was 0.75% ropivacaine 11.25 mg plus fentanyl 15 μg in both groups. Each dose was classified as effective if, after 15 min and during the next 60 min, there was inability to appreciate pin-prick as sharp at T4, a visual analogue pain score <2 and no requirement for an epidural rescue bolus.ResultsEighty patients were included in the analysis. The ED50 in group Ca was significantly higher (13.09 mg, 95% CI 12.19–14.00) than in group Ce (10.10 mg, 95% CI 9.54–10.65, P <0.001).ConclusionThe orientation of the distal aperture of a 26-gauge Whitacre needle during induction of spinal anesthesia for cesarean delivery influences the ED50 of 0.75% ropivacaine.     

Prediction of spinal anesthesia-induced hypotension during elective cesarean section: a systematic review of prospective observational studies

BackgroundSpinal anesthesia is the standard for elective cesarean section but spinal anesthesia-induced hypotension remains an important problem. Accurate prediction of hypotension could enhance clinical decision-making, alter management, and facilitate early intervention. We performed a systematic review of predictors of spinal anesthesia-induced hypotension and their predictive value during cesarean section.MethodsPubMed, Embase, Cochrane Library, Google Scholar and Web of Science databases were searched for prospective observational studies assessing the diagnostic accuracy of predictors of spinal anesthesia-induced hypotension in elective cesarean section. The quality of studies was assessed and predictors were grouped in domains based on the type of predictor.ResultsThirty-eight studies (n=3086 patients) were included. In most studies, patients received 500–1000 mL crystalloid preload or 500–2000 mL crystalloid coload. Vasopressors for post-spinal hypotension were boluses of ephedrine 5–15 mg and/or phenylephrine 25–100 µg in most studies. The hypotension rate varied from 29% to 80% based on the definition. For analysis, >30 predictors were classified into seven domains: demographic characteristics, baseline hemodynamic variables, baseline sympathovagal balance, postural stress testing, peripheral perfusion indices, blood volume and fluid responsiveness indices, and genetic polymorphism.ConclusionsEnvironmental and individual factors increased outcome variability, which restricted the value of the autonomic nervous system and peripheral perfusion indices for prediction of spinal anesthesia-induced hypotension. Supine stress tests may reflect parturients’ cardiovascular tolerance during hemodynamic fluctuations and may optimize the predictive value of static state predictors. Future research for predicting spinal anesthesia-induced hypotension should focus on composite and dynamic parameters during the supine stress tests.     

Performance of non-invasive stroke volume variation during passive leg raising as a predictor of hypotension following induction of spinal anesthesia for elective cesarean delivery: a single cohort study

BackgroundSpinal anesthesia for cesarean delivery is accompanied by hypotension in up to 70% of cases. To date, there is no gold standard for predicting hypotension after spinal anesthesia for cesarean delivery. The Clearsight™ device is a non-invasive system that uses a digital cuff to calculate stroke volume. We hypothesized that stroke volume variation induced with passive leg raising before spinal anesthesia for elective cesarean delivery could predict the occurrence of hypotension.MethodsWe conducted a prospective observational study, including third trimester parturients undergoing elective cesarean delivery with spinal anesthesia. We analyzed the stroke volume variation performance for predicting hypotension. Stroke volume was collected in the semi-recumbent position (baseline) and during passive leg raising before spinal anesthesia. Systolic arterial blood pressure measurement was followed for 15 min after spinal anesthesia. Hypotension was defined as a ≥20% decrease from the baseline measurement. All parturients received appropriate hypotension prophylaxis.ResultsData from 42 parturients were analyzed. Hypotension occurred in 45%. The area-under-the curve for predicting hypotension using the stroke volume variation was 0.83 (95% CI 0.68 to 0.98; P=0.001). The best cut-off value for predicting hypotension was 7%, having a sensitivity of 87% (95% CI 0.70 to 0.99) and a specificity of 83% (95% CI 0.69 to 0.97).ConclusionIn our study of third trimester parturients undergoing cesarean delivery and receiving appropriate hypotension prophylaxis, a digital non-invasive monitoring device of stroke volume variation analysis was useful for predicting the occurrence of hypotension after spinal anesthesia.     

A prospective study of post-cesarean delivery hypoxia after spinal anesthesia with intrathecal morphine 150 μg

IntroductionDelayed respiratory depression is a feared complication of intrathecal morphine in patients undergoing cesarean delivery. The incidence, timing and risk factors for hypoxia in this population are not known.MethodsPatients undergoing cesarean delivery under spinal anesthesia at a tertiary care center from October 2012 to March 2016 were included in the study. The Berlin sleep apnea Questionnaire was completed before surgery. Oxygen saturation was recorded every second for 24 hours after the initiation of spinal anesthesia. Desaturation events were defined as a median saturation of <90% (mild) or <85% (severe) across a 30-s period. Multivariable logistic regression was used to determine predictors of a desaturation event.ResultsA total of 721 patients were included in the analysis. Within this cohort, 169 women (23%) experienced at least one mild desaturation event, 91 (13%) experienced two or more mild desaturations, and 26 (4%) suffered a severe desaturation event. After the administration of intrathecal morphine, the median times to first mild or first severe desaturation were 7.4 (IQR 4.1–13.5) h and 12.0 (IQR 5.4–19.6) h, respectively. Patients who screened positive for sleep apnea had increased odds of having a mild desaturation event (OR 2.31, 95% CI 1.40 to 3.79, P=0.001), as did patients who were obese (OR 1.80, 95% CI 1.05 to 3.09, P=0.033).ConclusionsMild hypoxemia occurred frequently in women receiving intrathecal morphine 150 μg for post-cesarean analgesia. Desaturations were observed most frequently 4–8 hours after administration of intrathecal morphine. Obesity and a positive Berlin Questionnaire were risk factors for hypoxemic events.     

A comparison of epidural and cerebrospinal fluid glucose in parturients at term: an observational study

BackgroundDetecting inadvertent dural puncture during labour epidural insertion can be difficult when using a loss of resistance to saline technique. Testing fluid for glucose that leaks from a Tuohy needle may confirm the presence of cerebrospinal fluid and infer inadvertent dural puncture. This study compared the glucose content of intrathecal fluid obtained during spinal anaesthesia for elective caesarean delivery with that of fluid from a Tuohy needle or epidural catheter when establishing epidural analgesia for labour.MethodsWomen aged ?18 years undergoing elective caesarean delivery and labouring parturients who requested epidural analgesia were recruited prospectively in a tertiary referral centre over a three-month period. Fluid was collected into a sterile container either during spinal anaesthesia or from a labour epidural needle. Glucose content was evaluated using a bedside blood glucometer and laboratory colorimetric analyzer.ResultsOf the 118 women approached, 115 participated. All 40 women having spinal anaesthesia and 2/75 (2.7%) women having epidural analgesia, in whom inadvertent dural puncture was subsequently confirmed, had fluid samples testing positive for glucose. Median [range] laboratory glucose readings were 2.9 [1.3–5.1] mmol/L for cerebrospinal fluid and <0.3 mmol/L in fluid that leaked from a Tuohy needle (P = 0.0001).ConclusionWhen using a loss of resistance to saline technique for epidural catheter placement, bedside glucometer testing of fluid leaking from the epidural needle may be of value in the early detection of inadvertent dural puncture.     

Effects of intravenous ondansetron and granisetron on hemodynamic changes and motor and sensory blockade induced by spinal anesthesia in parturients undergoing cesarean section

BackgroundSpinal anesthesia has many advantages for cesarean section parturients, but hypotension is considered the most frequent complication and can be managed by different interventions. One of these interventions is to give a serotonin receptor antagonist prior to spinal anesthesia.ObjectivesTo compare between two serotonin receptor antagonists on the hemodynamics, sensory, and motor blockade induced by intrathecal bupivacaine in parturients undergoing cesarean section.Patients and methodsSixty patients undergoing elective cesarean section under spinal anesthesia by intrathecal bupivacaine were randomly divided into three groups (20 pregnant females of ASA I–II physical status in each group). Group O received intravenous 4 mg ondansetron diluted in 10 ml normal saline and injected over 1 min, 5 min before spinal anesthesia, group G given intravenous 1 mg granisetron by the same route and group S given 10 ml normal saline. Mean arterial blood pressure, heart rate, vasopressor use, sensory, and motor blockade were assessed.ResultsDecreases in mean arterial pressure were significantly lower in group O than groups G and S with lower vasopressor use (P < 0.05), while there was significant faster sensory recovery in group G than groups O and S (P < 0.05). Actually, there were significant decrease in the incidence of nausea in groups O and G than group S (P = 0.008).ConclusionIn parturient females undergoing elective cesarean section, intravenous 4 mg ondansetron before subarachnoid block significantly decreased both the hypotension and the doses of vasopressor used, while intravenous 1 mg granisetron prior to subarachnoid block induced faster sensory recovery compared to both the ondansetron and the saline groups, with no significant differences between the later two groups.     

Influence of burn severity on endothelial glycocalyx shedding following thermal trauma: A prospective observational study

ObjectiveSevere burns cause hypermetabolic and inflammatory responses are treated with significant volume resuscitation. This study aimed to evaluate correlations between glycocalyx metabolites and the burn size as well as certain clinical parameters such as administered fluid volumes.Study designSeverely burned patients with a total body surface area (TBSA) burned smaller and larger than 20% were included. Clinical parameters including length of stay, mortality, fluid administration and Sequential Organ Failure Assessment (SOFA) score as well as syndecan and heparansulfate, as laboratory parameters for endothelial damage, were obtained.ResultsA total of 39 patients (32 males, 7 females) with a mean age at burn of 45 ± 21 years were included. Syndecan levels decreased and heparansulfate levels increased over time. In both heparansulfate and syndecan, there was no significant difference between burns smaller and larger than 20% TBSA at any time point. Syndecan levels at 24 h after burn correlated significantly with IL-10 levels at admission (R = 0.58 and p < 0.05). There were significant linear correlations of %TBSA and cumulative administration of fluids after 24 h on syndecan levels after 48 h. Correlations between clinical parameters and syndecan or heparansulfate levels over time were not found.ConclusionsThis study shows that even though there are moderate correlations with burn size and administered fluid volume, levels of syndecan and heparansulfate are not predictive for clinical outcomes of burned patients in our cohort. Further studies with higher numbers evaluating the effect of large burns on glycocalyx shedding over a longer period of time are needed. Showing significant glycocalyx shedding in large burn including potentially correlations with clinical outcomes may yield new therapeutic targets.     

Neuraxial anesthesia in ex utero intrapartum therapy for parturients with fetal congenital diaphragmatic hernia: a prospective observational study

BackgroundCongenital diaphragmatic hernia (CDH) is characterized by defects in the fetal diaphragm and thoracic herniation of the abdominal viscera. The ex utero intrapartum treatment (EXIT) procedure is used to establish the fetal airway while on placental support. These EXIT procedures are commonly performed under general anesthesia, which increases maternal bleeding and the risk of insufficient placental perfusion subsequently. This study investigated the feasibility of performing neuraxial anesthesia for the EXIT procedure for fetal congenital diaphragmatic hernia to improve outcomes.MethodsParturients with fetal CDH who underwent an EXIT procedure between January 2019 and May 2021 in our institution were recruited. Variables evaluated included gestational age, surgical time, intra-operative blood loss, peri-operative hemoglobin, maternal complications, fetal lung-to-head ratio, time on placental bypass, and postnatal outcome.ResultsTwenty-two cases were included. All procedures were performed under neuraxial anesthesia. The median gestational age at the time of the EXIT procedure was 37 weeks. The median estimated blood loss was 200 mL. There was no report of an adverse maternal event. The placental bypass time was 142.9 ± 72.6 s, and access to the airway was successfully established within the bypass time. Twenty-one neonates reached an Apgar score of 9 at 5 min. In the first two hours after birth, the average pH of neonatal peripheral arterial blood was 7.35 ± 0.07 (n=19), and lactate level 1.85 ± 0.71 mmol/L (n=19).ConclusionsIn the EXIT procedure to establish an airway for fetal CDH, neuraxial anesthesia proved a feasible technique for maternal anesthesia.     

Heart rate variability as a predictor of hypotension following spinal for elective caesarean section: a prospective observational study

Post‐spinal hypotension remains a common and clinically‐important problem during caesarean section, and accurate pre‐operative prediction of this complication might enhance clinical management. We conducted a prospective, single‐centre, observational study of heart rate variability in 102 patients undergoing elective caesarean section in a South African regional hospital. We performed Holter recording for ≥ 5 min in the hour preceding spinal anaesthesia. The low‐frequency/high‐frequency ratio component of heart rate variability was compared, using a logistic regression model, with baseline heart rate and body mass index (BMI) as a predictor of hypotension (defined as systolic arterial pressure < 90 mmHg) occurring from the time of spinal insertion until 15 min after delivery of the baby. We also assessed clinically relevant cut‐point estimations for low‐frequency/high‐frequency ratio. Low‐frequency/high‐frequency ratio predicted hypotension (p = 0.046; OR 1.478, 95%CI 1.008‐1.014), with an optimal cut‐point estimation of 2.0; this threshold predicted hypotension better than previously determined thresholds (p = 0.003; c‐statistic 0.645). Baseline heart rate (p = 0.20; OR 1.022, 95%CI 0.988‐1.057) and BMI (p = 0.60; OR 1.017, 95%CI 0.954‐1.085) did not predict hypotension. Heart rate variability analysis is a potentially useful clinical tool for the prediction of hypotension. Future studies should consider a low‐frequency/high‐frequency ratio threshold of 2.0 for prospective validation.     

Prophylactic glycopyrrolate prevents bradycardia after spinal anesthesia for Cesarean section: a randomized, double-blinded, placebo-controlled prospective trial with heart rate variability correlation

Study Objective

To determine if prophylactic glycopyrrolate prevents bradycardia after spinal anesthesia.

Design

Prospective, randomized, double-blinded, placebo-controlled study.

Setting

Large university-affiliated community hospital.

Patients

81 consecutive term parturients (not in active labor) who were scheduled for elective Cesarean section.

Interventions

Parturients received 1.0 to 1.5 L of intravenous Ringer's lactate and either glycopyrrolate 0.4 mg or an equal volume of saline, with caregivers blinded to the immediate sequelae of study drug. Each patient received intrathecal bupivacaine (12 to 14 mg) with morphine sulfate (0.1 to 0.2 mg).

Measurements

Continuous heart rate (HR) and blood pressure monitoring occurred for 20 minutes, with the minimum HR recorded for each 5-minute epoch. Heart rates < 60 beats per minute defined bradycardia. Heart rate variability (HRV) analysis occurred offline.

Main Results

None of 34 patients administered glycopyrrolate and 6 of 35 (17%) patients receiving saline experienced bradycardia (P = 0.02476). Time domain, frequency domain, and nonlinear and embedded spectrum entropy analyses all reflected the decrease in HRV accompanying administration of glycopyrrolate.

Conclusion

Bradycardia after spinal anesthesia occurs commonly. Prophylactic glycopyrrolate may prevent the bradycardia, but not necessarily the hypotension.     

Urethral catheterization in spinal surgery: a randomized prospective study

Summary In a prospective randomized study the effect of the use of an intraoperative indwelling urethral catheter (IUC) on urinary complications was investigated in patients undergoing spinal fusion. Two groups were formed; 16 patients received an intraoperative IUC and 16 patients had no intraoperative catheter (NC). All patients were, if necessary, intermittently catheterized in the postoperative period. Seven of the patients in the IUC group had positive cultures, defined as 100000 CFU/ml, compared with two patients in the NC group (n.s.). Another four patients in the NC group had cultures 10000 CFU/ml. Thirteen patients in the IUC group and 14 patients in the NC group had positive dip slides. The largest received urine volume in each patient at one intermittent catheterization did not differ significantly between the groups. However, in three patients in the NC group the volumes exceeded 1000 ml. Thus, irrespective of treatment dip slides showed bacteriuria in 84% of the patients. Perioperative indwelling catheters do not seem to cause many more infection complications than no bladder drainage during surgery, and the advantages of reduced risk of bladder distension injury and more accurate monitoring of fluid balance suggest their use.     

Comparative study between ephedrine infusion vs. CO/post loading of fluids for prevention of hypotension in emergency cesarean section under spinal anesthesia

IntroductionMaternal hypotension is the most common complication during cesarean section under spinal anesthesia. The aim of this study was to compare the effectiveness of CO/post loading of fluids versus immediate post spinal infusion of ephedrine in prevention of hypotension.MethodsNinety healthy pregnant patients ASA I with single term fetus arrived to the operating room with nonlife threatening cause for emergency cesarean section under spinal anesthesia. The patients were allocated randomly into 3 groups, Group R: started the CO/post loading at the time of spinal injection and continued after it with 0.5 ml/kg/min Lactated Ringer's solution until delivery of the fetus. Group V: started the CO/post loading with 0.5 ml/kg/min Voluven at the same period. Group E: started ephedrine infusion at 1 mg/min via the infusion pump immediately after spinal anesthesia until delivery of the fetus.ResultsThe systolic blood pressure changes were statistically significant but they failed to reach clinical significant values in the three groups. The total dose of ephedrine was significantly higher in Ephedrine group than the other two groups. Intraoperative heart rate increased in the first 30 min in Ephedrine group without any clinical significance. All fetal data were within normal range and comparable between groups. Apger score of the fetuses was not less than 8 in the three groups. The incidence of nausea and vomiting was higher in group R and group V compared to group E.ConclusionIntravenous infusion of ephedrine 1 mg/min immediately after spinal anesthesia for emergency cesarean sections, even if there is no enough time for proper prehydration, can control effectively the hypotension without episodes of hypertension or significant tachycardia, and it had no effect on fetal well-being. It could be as effective as CO/post loading of 0.5 ml/kg/min lactated Ringer or Voluven in controlling systolic blood pressure with fewer incidences of post operative complications.